MAPT and neurodegenerative disease: Second, as extensively reviewed by Corsi et al. (2022), there are many hnRNP proteins [D, A3, H1, C, R, A2/B1, A1, G (RBMX), E2 (PCBP2), I (PTBP1), and PTBP2] that intricately regulate MAPT splicing, impacting the balance between various tau isoforms crucial for normal neuronal function and implicated in neurodegenerative diseases like Alzheimer’s disease.